bk commit into 6.0 tree (aelkin:1.2590) BUG#34686

[Andrei Elkin]

Below is the list of changes that have just been committed into a local
6.0 repository of aelkin.  When aelkin does a push these changes
will be propagated to the main repository and, within 24 hours after the
push, to the public repository.
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see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html

ChangeSet@stripped, 2008-03-08 12:14:47+02:00, aelkin@mysql1000.(none) +2 -0
  Bug #34686 change master w/o explict master_heartbeat_period dont reset
                 period to default
      
      The original patch has been pushed to 5.1-telco-6.3.
      This separate one is for 6.0 because merging is in reverse:
      6.0->telco.
      
  CHANGE Master w/o the explicit  master_heartbeat_period is supposed to
  reset the period to the value of @@global.slave_net_timeout/2.
  However, there was a possibility to get the hb status un-reset preserving its
  former value.
  Fixed with adding a rule to reset to the default in change_master().
  sql/sql_repl.cc
  ensuring hb repiod gets reset to the specified default.

  mysql-test/suite/rpl/t/rpl_heartbeat.test@stripped, 2008-03-08 12:14:45+02:00,
aelkin@mysql1000.(none) +10 -1
    adding explanation to disable_warnings instuction.

  sql/sql_repl.cc@stripped, 2008-03-08 12:14:45+02:00, aelkin@mysql1000.(none) +3 -0
    ensuring hb repiod gets reset to the specified default.

diff -Nrup a/mysql-test/suite/rpl/t/rpl_heartbeat.test
b/mysql-test/suite/rpl/t/rpl_heartbeat.test
--- a/mysql-test/suite/rpl/t/rpl_heartbeat.test	2008-02-03 11:00:47 +02:00
+++ b/mysql-test/suite/rpl/t/rpl_heartbeat.test	2008-03-08 12:14:45 +02:00
@@ -16,8 +16,17 @@ connection master;
 reset master;
 
 connection slave;
-set @@global.slave_net_timeout= 10;
 
+# there can be a warning if mtr set the global init value bigger than
+# the following assignment. The warning is a grace for the user
+# to warn her that the new value of the global var is bigger than
+# the current value of the hb period, i.e the sanity condition
+# 0 < hb < slave_net_timeout does not hold.
+# The warning has to be disabled as mtr can change the init value
+# for slave_net_timeout
+--disable_warnings
+set @@global.slave_net_timeout= 10;
+--enable_warnings
 ###
 ### Checking the range
 ###
diff -Nrup a/sql/sql_repl.cc b/sql/sql_repl.cc
--- a/sql/sql_repl.cc	2008-02-19 14:59:09 +02:00
+++ b/sql/sql_repl.cc	2008-03-08 12:14:45 +02:00
@@ -1255,6 +1255,9 @@ bool change_master(THD* thd, Master_info
     mi->connect_retry = lex_mi->connect_retry;
   if (lex_mi->heartbeat_opt != LEX_MASTER_INFO::LEX_MI_UNCHANGED)
     mi->heartbeat_period = lex_mi->heartbeat_period;
+  else
+    mi->heartbeat_period= (float) min(SLAVE_MAX_HEARTBEAT_PERIOD,
+                                      (slave_net_timeout/2.0));
   mi->received_heartbeats= LL(0); // counter lives until master is CHANGEd
   if (lex_mi->ssl != LEX_MASTER_INFO::LEX_MI_UNCHANGED)
     mi->ssl= (lex_mi->ssl == LEX_MASTER_INFO::LEX_MI_ENABLE);